Wall-board size



UNITED STATES PATENT OFFICE. V

BENJAMIN WILSON SIDWELL, OF BUFFALO, NEW YORK, ASSIGNOR TO THE BEAVER COMPANY, A CORPORATION OF OHIO.

WALL-BOARD sIzE.

No Drawing.

To all whom z'tma concern:

Be it known t at I, BENJAMIN VILSON Smwnnn, residin at Buffalo, in the county of Erie, State 0 New York, have invented certain new and useful Improvements in Wall-Board Size; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to a size suitable for use on articles formed from wood fiber, wood pulp, or the like, such, for instance. .as wall board.

Wall board may be made from wood fiber or wood pulp, either ground wood pulp,

waste aper or cooked pulp, used alone or intermixed, and ordinarily is marketed in substantially rigid sheets. The wall board may consist of a single layer of material or of a plurality of ies pasted or cemented together. General y it is used as a building material bynailing or tacking it directly to the studding of a room, so that it may serve in place of lath and plaster as the inner wall of the room, being usually ornamented with aint, or the like, as desired.

VVa 1 board, as manufactured, contains a certain percentage of moisture and also has the characteristic of changing in its moisture content in accordance with the humidity of the surrounding air; these changes ordinarily being slow but nevertheless appreciable. Such changes in moisture content are sometimes very troublesome in new buildings where the moisture initially present in the lumber, particularly green lum er, grad;

ually works through into the wall board,

causing expansion and sometimes warpin and buckling. The characteristic of We] board to absorb moisture extends also to paints, stains and similar decorative liquids, and if not counteracted leads to excessive waste of the decorative agent, as well as to unsatisfactory eflects.

The absorption of moisture and paint by wall board can be reduced by surface sizing. Thus, it has heretofore been customary to surface size wall board by applying a solution of gums, resins, and other. materials. As far as I am aware, however, an entirely satisfactory size for wall board has not here tofore been available, and the principal! object' of the present invention is the ro- Speciflcation of Letters Patent.

Patented Apr. 6, 1920.

Application filed November 30, 1918. Serial No. 284,056.

vision of an improved size artieularly adapted to be satlsfactorily app ied to wall board, and the like, under commercial manufacturing conditions.

The manufacture of wall board, as commercially carried out, is more or less of a continuous process. Thus, in the customary sizing o eration, the wall board panels are passed t rough a suitable sizing machine or apparatus and placed one upon another on a truck until several hundred panels are in one pile. Under these conditions the sizing liquid is given insufficient time to dry or oxidize in a film on the surface of the wall board, but on the other hand continues to penetrate instead of remaining on the surface of the board. The improved size of the present invention is designed to overcome these objections, and can be applied to panels, which are piled one on the other directly after comin from the sizing machines, without en angering the proper functioning of the surface coating as a satisfactory size.

Most sizing compounds are essentially resins, gums, or similar substances, treated for various purposes, and cut in some suitable solvent or solvents. The function of.

dation of the so vent, the protective material.

dries into a film coating. It has heretofore been customary in sizing wall board to use a sizing material which is a liquid at ordinary temperatures, and in such a size the solid ingredients are reduced to the desired liquid consistency at ordinary temperatures by means of sultable' solvents. In contradistinction to such sizing materials, the improved size of the present invention is solid at ordinary temperatures and is heated to a. temperature of from about 300 to 450 F., in order to obtain the desired fluid consistency for a plication to the wall board or other pro uct -to be sized. For these reasons, I have found it desirable to designate the size of the present invention as a hard size, in order to distinguish it from the customary liquid sizes heretofore used.

In the case of wall board, the protective material, which dries into the film coating. must not only be moisture proof to a very large extent, but must, in addition, present to use a smaller percentage a surface suitable for decoration b y paints and similar decorative agents. he 'improved size of the present invention is a compound or mixture of various substances in suitable proportions, which, when applied under proper conditions to wall board or other wood fiber products, satisfactorily fulfils the aforementioned requirements of a practical wall board size.

The protective or film coating material of the improved size comprises a suitable resin, such as ordinary rosin. or the like, and a waxy substance. such, for example, as paraflin wax. Ordinary rosin, at a temperature of from 400 to 450 degrees Fahrenheit, is a fairly thin liquid, and, when properly spread on a suitable surface, hardens, at ordinary temperatures. into a film coating. Such a film coating of rosin, however, is very brittle and soon dusts oif; neither is it moisture proof. The brittleness of rosin can be reduced by the addition of-oil, such. for example, as linseed, China wood, or similar oils. However.'too much oil added to rosin makes a tacky coating, which is decidedly objectionable in a wall board size, since it results in the sticking together of the panels when iled one above another. Moreover, the addition of ,oil to rosin, while acting as a binder, doesnot render the'rosin film moisture proof. It has been found, however, that by adding paraffin, or some other satisfactory wax. to a mixture of rosin and oil a ractical moisture proof film can be obtaine In compounding the improved size of the present invention, I take. for each 100 parts of resin, up to 15 parts of wax. I have found that for most cases a satisfactory mixture is produced by using about 5 parts of wax for each 100 parts of resin. Be-

sides improving the moisture proof roperties of the resultant film coating, t e wax lowers the melting point of the sizing compound. This ,is a very desirable result, since a satisfactory hard size, while solid at ordinary temperatures, should have a fairly low melting oint, while at the same time containing su cient binders and driers.

The amount of parafiin .or other wax admixed with the resin is dependent upon the degree of moisture proofness desired. However, if too much wax is added the sized surface will be too greasy for the proper application of ainting or decorative materials. For thls reason the sizing compound should not contain over 10% by weight of wax,

or as stated above, not more than about 15 parts of waxshould be mixed with each 100 parts of resin. Ordinarily, I prefer of wax, and I have found a sizing com and containing proximately 4% by weight of wax well a adapted for wall board.

I have found that the addition of manarts for each ganese dioxid up to about 5 ant resin, ma-

100 parts of rosin, or equiva terially improves the properties of the size. Manganese dioxid is a powerful drying agent, and its use, within the proportions herein contemplated, does not increase the melting point of the size compound. I have found about 3 parts of manganese dioxid with about 100 parts of resin and about 5 parts of wax to give good results.

I have further found the addition of lime up to about 3 parts for each 100 parts of resin to be beneficial. Lime (calcium oxid), or calcium hydrate, acts both as a drier and hardener. Its use raises the melting oint of the size compound, and as a result 0 this property it is advantageous to use a larger pro ortion of lime in warm weather. Such an increase in the amount of lime in the size compound increases the hardness of the composition at ordinary temperatures, andifziliereby prevents the production of a tacky Any oil having the faculty of binding resins, gums, or the like, into compositions which will form films on drying or hardening can be used as the binder in my improved size. I refer, however, to use China wood oil. he amount of oil to be used will depend upon the conditions under which the size is to be used. Generally, I have found that from one to three gal ons of China wood oil for each 100 lbs. of resin give good results. The amount of oil used may be raised or lowered according to the temperature of the atmosphere at the time of applying the size. The toughness of the film coating may also be controlled to some extent by the amount of oil used.

A portion of the oils hereinbefore mentioned may be replaced by kerosene oil, or equivalent saturated hydrocarbon. Kerosene oil acts as a thinner and also reduces the meltin point of the size compound. The use of Irerosene oil, of course, affects the binder of the resin, and in this respect it is inferior to the siocative oils. Up to about one and one-half gallons of kerosene or equivalent thinner for each 100 lbs. of resin may be used to advantage.

In the foregoing description, I have indicated the general proportions of the various 7 ingredients of my lmproved sizing compound. For a plication to wall board, I

have found a size containing these ingredicats in about the following proportion to give good results:

Classing manganese dioxid, lime, and uivalent substances, as driers and hardeners, the general percentages of the various ingredients in my improved size are represented 1n the following table:

!, 85 b wei ht.

Wax Hardeuers and driers Binder 10m 25 0 The improved size of the present invention is solid at ordinar temperatures. Its melting point can be controlled to a considerable extent by suitably proportioning the various ingredients. as hereinbefore indicated. As a size for wood fiber products, the sizing compound should melt at a temperature below about 300 degrees Fahrenheit. so that at or slightly above this temperature the compound is a liquid suitable for the sizing operation. .\s applied to wall hoard, I prefer to maintain the sizing compound at a temperature from about 300 to 450 degrees Fahrenheit. and I have found that the specific formula hereinbet'ore mentioned gives substantially the desired degree of penetration to successfully seal and waterproof the wall hoard when applied at a temperature between these limits.

The size of the present invention possesses excellent moisture repellent properties. This is largely due to the wax. but at the same time it should he noted that the presence of the wax does not result in the production of an unpaintable sized surface. This is in large partdue to the relatively small amount of wax employed. and also to the fact that the relatively greater proportion of resin together with the driers and hardeners used render the wax content hard. and thus counteract its inherent greasy charactcristic.

The improved size has no injurious effect upon the fiber. and is of such transparency aml color that the original appearance of the surface to which it is applied is little changed. The size dries readily and without the necessity of racking or air drying the articles treated, and furthermore enhances the painting and decorating possibilities of the sized surface.

it is to he understood that the size may be applied in any convenient manner. I wish it also to be understood that while I have made particular reference to the use of the size for wall board. the sizeis of such a composition that it may he used extensively in the art. more particularly in connection with products made from wood fiber, wood pulp, and the like.

I claim: 1. A size for wood fiber products and the like, containing from about 65 to 85% by weight of resin, from about 1 to 10% by weight of wax, and from about 10 to 25% by weight of a binder.

:2. size for wood fiber products and the like. consisting essentially of resin, wax, a binder. and hardeners and driers in about the proportion by weight of 65 to 85% resin, l to 109; wax, 10 to 25% binder, and 1 to 1 hardeners and driers.

3. A size for wood fiber products and the like, containing resin, wax and China wood oil in about the proportions by weight of 65 to 851 resin. 1 to 10"; wax. and 10 to 25% (hina wood oil.

4. size for wood fiber products and the like containing resin. wax, and a binder in about the proportion by weight of resin, if} wax, and 1a to 20% binder.

5. A size for wood fiber products and the like. containing resin, wax, manganese di' oxid and a binder.

6. A size for wood fiber products and the like, containing resin, wax. manganese dioxid, lime and a binder.

T. A size for wood fiber products and the like, containing resin, wax, and'from about 10 to 25 by weight of (hina wood and kerosene oils as a binder.

h. size for wood fiber products and the like. containing resin, wax, a binder, and from 1 to 39; by weight of manganese dioxid.

9. size for wood fiber products and the like. containing resin, wax. a binder, and from 1 to 5); by weight of manganese dioxid and lime.

10. A size for wood fiber products and the like. containing about 757} by weight of resin, about 2% by weight of manganese di oxid, about 1% by weight of lime, about 4% by weight of wax, and about 18% by weight of a binder.

11. A size for wood fiber products and the like. containing about 75% b weight of resin. about 4% by weight 0 wax, about 18% by wei ht of a binder, and about 3% by weight of hardeners and driers.

12. A size containing about 7 5% by weight of resin and about 4% a binder.

In testimony whereof I aflix my si nature.

BENJAMIN WILSON SID ALL.

by weight of wax and i 

